Irish leaders drunk on Spanish sparkling wine and expensive food (6)
I believe the answer is:
caviar
'expensive food' is the definition.
'caviar' can be an answer for 'food' (caviar is a kind of food). I am not sure about the 'expensive' bit.
'irish leaders drunk on spanish sparkling wine' is the wordplay.
'leaders' suggests taking the first letters.
'drunk' is an insertion indicator (inserted letters are drunk in).
'on' is a charade indicator (letters next to each other).
'spanish' becomes 'r' (I can't justify this - if you can you should believe this answer much more).
'sparkling wine' becomes 'cava' (Spanish sparkling wine).
The first letter of 'irish' is 'i'.
'r' after 'cava' is 'cavar'.
'i' put within 'cavar' is 'CAVIAR'.
'and' is the link.
Can you help me to learn more?
(Other definitions for caviar that I've seen before include "Sturgeon's roe" , "Fish roe" , "Salted roe of sturgeon" , "Sturgeon delicacy" , "Sturgeon eggs" .)